Multilocus phylogeography of the world populations of Elaeidobius kamerunicus (Coleoptera, Curculionidae), pollinator of the palm Elaeis guineensis

Abstract Elaeidobius kamerunicus Faust (Coleoptera, Curculionidae) is one of the specific pollinators on inflorescences of the African oil palm Elaeis guineensis Jacquin. This derelomine weevil is native to tropical Africa. During the late 20th century, it was introduced into all tropical regions where E. guineensis is grown, in order to improve its pollination and fruit set. Despite an overall success, a decline in pollination efficiency has been documented in several regions. In this study, we reconstructed a multilocus phylogeography of the world populations of E. kamerunicus, in order to explore its genetic diversity in its native and introduced ranges. Our results showed that African populations of E. kamerunicus are forming two differentiated mitochondrial clusters in West and central Africa, forming a contact zone along the Cameroon Volcanic Line. The existence of this sharp contact zone along this weak altitudinal barrier suggests that other parameters, such as climate, may be driving the distribution of populations. A differential genetic structure between mitochondrial and nuclear genes, and the strong level of genetic structure of the mitochondrial gene, also suggest sex-biased dispersal in this species, with males dispersing more than females. The genetic structure inferred from Asian and South American populations suggests that they originate from populations of both western and central tropical Africa and that a bottleneck has probably been experienced by these populations.